Pyrano[3,2-a]carbazole alkaloids as effective agents against ischemic stroke in vitro and in vivo
摘要:
A series of pyrano[3,2-a]carbazole alkaloids were designed and synthesized as analogues of Claulansine F (Clau F, 10a) isolated from Clausena lansium. Some of compounds showed strong neuroprotective effects and were promising agents against ischemic stroke. Among these compounds, 7c was the most active in inhibiting the programmed death of PC12 cells and primary cortical neurons. This compound induced neuroprotection following ischemic reperfusion and decreased neurological deficit scores in treated animals. Furthermore, 7c could penetrate the blood-brain barrier (BBB) in rats, and its exposure in the brain was 4.3-fold higher than that in plasma. More importantly, compared to edaravone, 7c exhibited stronger free radical scavenging activity. Our findings suggest that 7c may be promising for further evaluation as an intervention for ischemic stroke. (C) 2017 Elsevier Masson SAS. All rights reserved.
Transition Metals in Organic Synthesis, Part 91:¹ Palladium-Catalyzed Approach to 2,6-Dioxygenated Carbazole Alkaloids - First Total Synthesis of the Phytoalexin Carbalexin C
作者:Hans-Joachim Knölker、Marika Schmidt
DOI:10.1055/s-0029-1217810
日期:2009.9
The palladium(0)-catalyzed C-N bond formation and palladium(II)-catalyzed oxidative cyclization provide an efficient route to a series of 2,6-dioxygenated carbazole alkaloids including the first totalsynthesis of the phytoalexin carbalexin C.
钯 (0) 催化的 CN 键形成和钯 (II) 催化的氧化环化为一系列 2,6-二氧化咔唑生物碱提供了有效途径,包括植物抗毒素卡巴莱辛 C 的首次全合成。
Synthesis of 1,1′- and 2,2′-Bicarbazole Alkaloids by Iron(III)-Catalyzed Oxidative Coupling of 2- and 1-Hydroxycarbazoles
作者:Christian Brütting、Raphael F. Fritsche、Sebastian K. Kutz、Carsten Börger、Arndt W. Schmidt、Olga Kataeva、Hans-Joachim Knölker
DOI:10.1002/chem.201704554
日期:2018.1.9
We describe the synthesis of 1,1′‐ and 2,2′‐bicarbazoles by oxidative homocoupling of 2‐ and 1‐hydroxycarbazoles. The oxidative coupling using catalytic amounts of F16PcFe can be applied to both groups of substrates. Although F16PcFe generally provides the best yields for the synthesis of 1,1′‐bicarbazoles, di‐tert‐butyl peroxide affords better results for the 2,2′‐bicarbazoles. In our study, we have
Using the palladium(II)-catalyzed oxidative cyclization of a diarylamine and the annulation of a dimethylpyran ring by Lewis acid promoted reaction with prenal as key steps, the total syntheses of the 6-oxygenated pyrano[3,2-a]carbazole alkaloids koenine and koenimbine, and of the 6,7-dioxygenated pyrano[3,2-a]carbazole alkaloids koenigine and koenigicine (koenimbidine, koenidine) were achieved. Moreover, these studies led to an improved synthetic route to the 2,6-dioxygenated carbazole alkaloid glycozolidol. Mukonicine, originally published as 6,8-dimethoxypyrano[3,2-a]carbazole, was found to be identical with koenigicine.